Improvement in burglar-alarms



A. P. NORMAN.

BURGLAR-ALARM. r

Patented June 20,1876.

@fm/WM5@ N'FETES. FHDTO-LITHUGRAPNER. WASHINGTON. D CA UNITED STATES PATENT OFFICE.

ADOLPHUS iP. NORMAN, OF NEW YORK, N. Y.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 178,875, dated June 20, 1876; application filed April27, 1876.

To all whom it may concern y Be it known that I, ADoLPHUs P. NORMAN,

v of the city and State of New York, have ineasily be carried by travelers and others, and

attached wherever necessary for the protection ot' person or property. i

Alarms have been made with a bell and a spring that is wound up by revolving the bell.

. My invention relates to this general class of alarms; and consists-in a peculiar construc tion ofescapement and trip 5 also, in the means for attaching the'alarm.

In the drawing, Figure 1 is au elevation of the alarm with the bell removed, 'and with a part of the bridge taken away, so as to show the escapement; and Fig. 2 is a vertical sectionat the line x x.

The plate a is provided with a slot, through which the attaching-screw b passes to secure the plate to the casing of the door, or to the window or sash. This screw b has a winged head, so as to be operated by hand. There is a spring, c, attached to the plate a., and through the curved end ofthis spring c the screw passes, and it is attached by a washer, e, so that the screw is always connected to` the spring, but it isfree to be turned. The curvature of the springis such as to turn the screw into an inclined position, and draw the point back into the position shown by dotted lines in Fig. 2, in order that the point of the screw may not project to tear or injure the clothing in transportation.

When the alarm is connected to its place Athe gimlet`pointed screw Z2 compresses the spring as it is screwedinto the wood. A

bridge, f, is attached to the plate a, and passes one end of the spring is attached to the arbor, and the other to the spring-barrel g. The

'ratchet-wheel k is upon the squared end of the arbor t', and there is a pawl and spring, l, upon the bridge, to hold the spring when wound. The bell m also sets upon this arbor i, and is held by a nut, n, so that the spring ofthe spring-barrel g is wound by revolving the bell. The hammer o is upon a pivot, 2,

and it is connected with pallets r, adjacent to turned into the position shown by full lines, it-

springs down behind the inclined stud 4, and is held by the same, and blocks the escapement so that it cannot move. There is a spring, u, around the stud 3, that tends to throw the trip tinto the position shown by dotted lines in Fig. l., and also to draw the hammer back from the bcll. The end of the trip t projects beyond the outside of' the base a, and the al'arm is to be positioned so that the spring trip will be moved bythe door or window as it is opened, and in so doing the alarm will be rung until the spring runs down.

I claim as my invention- 1. In combinationY with the bell, escapement, and hammer, the spring-trip t, pivot 3, inclined stud 4, and spring u, the parts being constructed and operating as set forth.

2..'lhe gimlet-pointed screw b and curved spring c, in combination with the base-plate a and burglar-alarm, for the purposes, and as set forth.

Signed by me this 22d day of April, A. D. 1876.

A. P.' NORMAN. 

